fix(http): Fix HttpHook.url_from_endpoint() lazy initialization

providers/http/src/airflow/providers/http/hooks/http.py

@@ -135,6 +135,7 @@ def __init__(
         self.http_conn_id = http_conn_id
         self.method = method.upper()
         self.base_url: str = ""
+        self._base_url_initialized: bool = False
         self._retry_obj: Callable[..., Any]
         self._auth_type: Any = auth_type
 
@@ -203,6 +204,7 @@ def _set_base_url(self, connection) -> None:
         parsed = urlparse(self.base_url)
         if not parsed.scheme:
             raise ValueError(f"Invalid base URL: Missing scheme in {self.base_url}")
+        self._base_url_initialized = True
 
     def _configure_session_from_auth(self, session: Session, connection: Connection) -> Session:
         session.auth = self._extract_auth(connection)
@@ -383,6 +385,10 @@ def run_with_advanced_retry(self, _retry_args: dict[Any, Any], *args: Any, **kwa
 
     def url_from_endpoint(self, endpoint: str | None) -> str:
         """Combine base url with endpoint."""
+        # Ensure base_url is set by initializing it if it hasn't been initialized yet
+        if not self._base_url_initialized and not self.base_url:
+            connection = self.get_connection(self.http_conn_id)
+            self._set_base_url(connection)
         return _url_from_endpoint(base_url=self.base_url, endpoint=endpoint)
 
     def test_connection(self):

providers/http/tests/unit/http/hooks/test_http.py

@@ -612,8 +612,31 @@ def test_keep_alive_disabled(self):
     def test_url_from_endpoint(self, base_url: str, endpoint: str, expected_url: str):
         hook = HttpHook()
         hook.base_url = base_url
+        hook._base_url_initialized = True  # Mark as initialized to prevent lazy loading
         assert hook.url_from_endpoint(endpoint) == expected_url
 
+    @mock.patch("airflow.providers.http.hooks.http.HttpHook.get_connection")
+    def test_url_from_endpoint_lazy_initialization(self, mock_get_connection):
+        """Test that url_from_endpoint works without calling get_conn() first."""
+        # Mock the connection
+        mock_connection = mock.MagicMock()
+        mock_connection.host = "foo.bar.com"
+        mock_connection.schema = "https"
+        mock_connection.port = None
+        mock_get_connection.return_value = mock_connection
+
+        # Create hook without calling get_conn() and verify that base_url is not initialized
+        hook = HttpHook(http_conn_id="test_conn")
+        assert not hook._base_url_initialized
+
+        # This should work now with our fix and verify the URL was constructed correctly
+        url = hook.url_from_endpoint("baz/bop")
+        assert url == "https://foo.bar.com/baz/bop"
+
+        # Verify get_connection was called and and verify that base_url is now initialized
+        mock_get_connection.assert_called_once_with("test_conn")
+        assert hook._base_url_initialized
+
     def test_custom_adapter(self):
         custom_adapter = HTTPAdapter()
         hook = HttpHook(method="GET", adapter=custom_adapter)